Syrian state television and medical sources in central Hama province swapped accusations Saturday over an attack that reportedly caused "suffocation and poisoning" of residents.
Medics quoted by the Syrian Observatory for Human Rights NGO said people choking from poisoning had been hospitalised after air raids with barrel bombs Friday on the town of Kafr Zita.
"Regime planes bombed Kafr Zita with explosive barrels that produced thick smoke and odours and led to cases of suffocation and poisoning," Observatory director Rami Abdel Rahman said.
But state television reported that Al-Qaeda affiliate Al-Nusra Front had released chlorine gas in a deadly attack on the town.
"There is information that the terrorist Al-Nusra Front released toxic chorine... leading to the death of two people and causing more than 100 people to suffer from suffocation," it said.
"There is information that Al-Nusra Front is preparing to hit Wadi Deif in Idlib province and Morek in Hama province with toxic chorine or sarin," the state broadcaster added.
There was no independent verification of either of the claims, which come after a chemical weapons attack outside Damascus last year.
The opposition and much of the international community blamed that attack, which reportedly killed as many as 1,400 people, on the Syrian regime.
The regime denied responsibility, in turn blaming rebels, but agreed under threat of US military action to turn over its chemical weapons stockpile for destruction.